If you are seeing wet loads in your autoclave we can help, this presentation helps show what a wet load is and why its important. It also includes some of the potential root causes of wet loads.

1. Porous Load
Autoclave
Wet Loads

2. What isawetload?
• When an autoclave load is removed from the
chamber, the load must be dry. In moist
environments microbial growth can occur.
• Dryness is difficult to define though, so at
what level is any condensate acceptable?
At Thermal Compliance we define it as, if
condensate can be detected by the senses, it is
not acceptable. Therefore you must not:
• See it
• Feel it

3. Autoclave
Basic overview of how a Porous Load Steam Steriliser works
Steam pressure is controlled to ensure
the drain is the correct temperature.
Baffle plates force steam to displace air
down the drain.
Condensate will collect if not allowed to free drain.

4. Potential Causes
Wet loads can be caused by several factors:
Steam Distribution / Steam Quality Issues
• Failed Steam Traps
• Steam Generator Issues
Autoclave
• Jacket Temperature
• Vacuum Pump Issues
• Fans. Pipework on Roof of Chamber
Load Design and Preparation
• Change in Load Wrapping
• Load Item Materials of Construction
• Poor Load Orientation
• Poor Load Wrapping

5. Potential Causes
Steam Distribution / Steam Quality
Step 1
Perform Steam Quality Testing (EN285:2015, PDA Technical Report 1)
• At Point of Use
• At Point of Generation
Step 2
Perform a Distribution Survey
• Check Steam Traps
• Pipe levels etc

6. Potential Causes
Load Design and Preparation
Ensure the bags used for wrapping
are specified correctly, ensure they
are:
• The right size for your items
• The right shape for your items
Load Wrapping
Cut bags to Size
Use suitable Size bags
Don’t fold over bags
Remove Excess
Wrap
Orientate the load to:
• Allow free draining
• Place large items on the bottom
shelf
• Consider where condensate
would be generated and how to
remove it
Orientation of Load
Paper/Plastic Bags should be
orientated with paper adjacent to
paper and plastic adjacent to plastic.
Bag placement

7. Potential Causes
Autoclave
The Jacket temperature should be below
sterilisation temperature. To allow
condensate to form and go to drain.
High Temperatures may cause superheat
and low temperatures may cause
condensate to rain onto the load.
Vacuum Pump
Check feed water temperature
Check pulse times and depths.
Does the wet load
correlate to ports, fans etc
in the Autoclave Roof?

8. 0201
ABOUT US
We deliver practical and online
training courses in:
• Autoclave Validation
• Temperature Mapping
• Steam Quality Testing
• Kaye Validator 2000
Training
We can help with:
• Wet Loads
• Superheat Investigations
• Equilibration Failures
• Steam Quality Failures
• Biological Indicator Failures
Consultancy 03We perform Validation on a
wide range of equipment:
• LN2 Freezers – Ovens
• Autoclaves and SIP
• Freeze Driers
• Dry Heat Processes
Validation

9. CONTACT US
Chris Maughan
Managing Director
Thermal Compliance
chrism@thermalcompliance.co.uk
www.thermalcompliance.co.uk
18 Harelands Courtyard Offices
Moor Road Melsonby
Richmond
DL10 5NY
UK
Tel +44 (0)1748 327 247
www.thermalcompliance.com
(Training Website)